ElementContext provides information about the current element being visited
and provides utilities for processing child elements, reporting logging
messages and storing information for use by other visitors.

An extension hook is responsible for processing information from the
extension manifest for a particular feature and making this information
available to the service responsible for managing the functionality
provided by the hook.

An exception indicating that an element was encountered that was
unexpected.

Package javax.ide.extension Description

Classes and interfaces used by extensions to extend
an IDE with new functionality. The extension hook interface provide the
integration entry points for the new functionality. There are several
extension hooks which are loaded independent of each other and only
when required.